STATE HOUSE ROUNDUP -- Two things that are certain

President Donald J. Trump and Senate President Stanley C. Rosenberg may finally have a common interest - tax reform.

While that may be the point where their shared agendas start to diverge, the topic that Beacon Hill leaders largely like to avoid may soon become something they can't escape.

The federal debate over tax reform appears headed toward a package of tax cuts, while Massachusetts voters will almost certainly be asked to decide in 2018 whether households should pay a surtax on incomes over $1 million to generate additional revenue for state government.

Enter Rosenberg, who in a speech to the Greater Boston business leaders last week pleaded with the community not to embrace the Retailers Association of Massachusetts's pitch for a sales tax cut as he took a stab at explaining a conundrum that has vexed budget writers for years now.

The strength of the state economy, including low unemployment, has done little to stabilize state finances or generate the tax revenue growth necessary for Democratic leaders to comfortably invest in education, rail expansions and other projects on their wish lists. March brought another round of collections that missed benchmarks, and the state now trails revenue projections for the year by $220 million with just three months left in the fiscal year.

Rosenberg suggested a tax system reliant on income gains and taxes on the sales of goods has failed to capture the nature of the new service-based economy.

The Amherst Democrat suggested it was "certainly worth looking at" a revival of the sales tax on business and professional services passed under Gov. Michael Dukakis and repealed by Gov. William Weld.

But even if that's just one suggestion, Rosenberg raised an interesting questions and one that might not soon go away. True tax reform has not been attempted since Gov. Deval Patrick, late in his second term, put a package on the table that would have raised the income tax, lowered the sales tax and eliminated a variety of exemptions, but it barely got a look by skeptical legislators.

House Speaker Robert DeLeo recognized the need for revenue in 2013, but opted for increases in gas and cigarette taxes that haven't produced the revenue jolt that DeLeo's 2009 sales tax hike did.

Gov. Charlie Baker may not be chomping at the bit to entertain straight tax hikes, but the possibility of more-comprehensive tax revamp is exactly the reason he refused to take a no-new-taxes pledge in 2014 when he was running for governor, and may be the opening Democrats need to start the debate, if not for now then perhaps the years to come.

The fight over how and when that is going to happen grows more interesting by the week, with House Marijuana Policy Committee Chairman Mark Cusack writing to the administration last week asking them to withhold $300,000 in authorized funding from Treasurer Deborah Goldberg.

Cusack essentially asked that spending be halted until lawmakers can settle the question of how the pot industry will be regulated.

Goldberg wants the money to begin hiring staff and preparing for the full implementation of the marijuana legalization law, but curiously, she doesn't seem to have much fight in her when it comes to defending her office's claim to the regulatory throne.

"Not at all," Goldberg said last week when asked if she was trying to dissuade the Legislature from giving authority to someone, or something else.

Even the routine isn't that routine anymore.

The House and Senate are at odds over how to fund local road and bridge repairs through the Chapter 90 program, an annual exercise that seldom makes for controversy. But after the House continued the recent traditional of passing a one-year, $200 million authorization, the Senate decided to stir the pot and go for a two-year bill at $400 million total.

Baker said he would consider signing a two-year bill, but the timing is becoming problematic. The lack of a deal between branch leaders is delaying the release of needed funding to communities who want to get a jump on the limited construction season.

Second, some of the more politically minded around the State House found it curious to try to switch to a two-year funding cycle now, in an odd-numbered year, rather than wait until next year so that lawmakers could take a popular vote during an election year.

Cities and towns aren't about to object to a multiyear bill after seeking one for years, but insiders say they're not exactly popping champagne either over the prospect of locking in funding at $200 million a year for multiple years when they want $300 million, at least.

A conference committee will now try to resolve the impasse before the Legislature breaks for school vacation week and the House becomes involved in its budget debate the week of April 24.

While the Legislature and Goldberg seem to be on a collision course over pot and the House and Senate battle over road funding, the Baker administration and Auditor Suzanne Bump also butted heads last week over Medicaid.

As the House prepared to release its budget redraft and answer the question of how it will handle MassHealth spending pressures, Bump released an audit detailing what she described as $193 million in improper or questionable payments made by MassHealth over the span of five years for behavioral health services.

The administration came back at Bump with a forceful rebuttal, denying all but $1 million in questionable spending and suggesting Bump's office had a "fundamental lack of understanding" about how behavioral health care is delivered.

Speaking of delivering, the feds signed off on the new cost estimates for the Green Line Extension into Somerville and Medford, meaning MassDOT now has the green light to start pushing that rail project forward.

Baker now has the ability to start making good on two long-promised rail expansions, even though critics like Sen. Marc Pacheco continued last week to question MassDOT's decision to pursue a course for South Coast rail that would require diesel engines and steer trains away from Taunton.

The passing of Sen. Kenneth Donnelly, who lost an eight-month battle with brain cancer, hung over everything on Beacon Hill last week, as friends and colleagues mourned the popular Arlington politician whose death caught many by surprise.

Possible candidates for Donnelly's seat were not ready to discuss politics so soon after the senator's passing, but it will be the first special election of the cycle and could draw interest from more than one House member.

Rep. Geoff Diehl, a Whitman Republican, already tried to win a state Senate seat, but now his eyes are on a bigger prize - the U.S. Senate. The maverick Republican took a step toward running for the Republican nomination in 2018 by opening a federal campaign account to begin raising money.

The exploratory phase for Diehl will last as long as he has questions about his ability to raise enough dough to compete with a well-funded Sen. Elizabeth Warren, who already has more than $4.8 million in the bank and will have little trouble raking in cash from around the country.

Diehl said he would like to see fundraising in the "strong six figures" before he feels comfortable launching a campaign, which might require him to fight for the nomination before he can even begin to think about toppling Warren.